Duplicating machine



Au 30, 1938.. c, H, BRADT 2,128,283

DUPLISATING MACHINE Filed March 12, 1937 2 Sheets-Sheet l INVENTORCHARLES h. BRADT ATTORNEYS Patented Aug. 30, 1938 UNITED STATES PATENTFHQE DUPLICATING MACHINE Application March 12, 1937, Serial No. 130,480

13 Claims.

This invention relates to improvements in duplicating machines, and moreparticularly to duplicating machines of the hectograph type.

In duplicating machines of the hectograph type it is a common practiceto lay and impress the master and copy sheets upon the surface of theresilient gelatinous or other duplicating medium by means of a sheetlaying and impression roller or platen roller mounted in a travelingcarriage. Considerable difiiculty has been had in transferring auniformly inked and undistorted negative impression from a master sheetto the gelatin surface, in transferring a uniformly inked andundistorted positive impression from the gelatin surface to a copysheet, in compensating for variations in thickness of sheets impressedupon the gelatin, and in preventing rupture of the gelatin by excessivepressure thereagainst.

The present invention has for its principal object to provide improvedsupporting and guiding means for the carriage, and particularly toprovide simple and effective means for so supporting and guiding thecarriage as to overcome the above difiiculties, obtain excellentimpressions irrespective of variations in level of the gelatin surfaceand variations in thickness of a sheet, and avoid liability of rupturingthe gelatin duplicating medium or composition.

Other objects and advantages of the invention will appear from thefollowing description of the preferred embodiment of the inventionillustrated in the accompanying drawings, and it is a purpose of theinvention to obtain any and all advantages with respect to structure andto operation which are inherent in the construction shown in thedrawings as constituting the preferred embodiment of the invention.

In the drawings, in which so much of a duplicating machine of thehectograph type is shown as is necessary to an understanding of thepresent invention:

Fig. 1 is a fragmentary side elevation of the machine, the travelingcarriage being shown posi- 45 tioned adjacent the front end of themachine with the impression or platen roller lowered to workingposition;

Fig. 2 is a fragmentary plan View of the machine, with the partspositioned as in Fig. l, a 50 part of the machine frame being shownbroken away;

Fig. 3 is a detail fragmentarl front elevation of the machine showingthe carriage mounting;

Fig. 4 is a detail fragmentary plan View show- 55 ing the carriagemounting;

Fig. 5 is a detail sectional view on the line 5-5 of Fig. 4;

Fig. 6 is a detail sectional view taken on the same line as Fig. 5 andshowing on an enlarged scale certain of the parts illustrated in Fig. 5;and

Fig. 7 is a view similar to Fig. 5, but showing the carriage swungupward and to the right from its working position shown in Figs. 1 to 6into an inoperative position in which the carriage is supportedLip-ended at the right hand side of the 10 machine to facilitate accessto the bed of the machine and the gelatin medium stretched over the bed.

The machine has a suitable frame Hi which supports a flat horizontal bedi i and includes two flat horizontal tracks l2 and 53. The tracks extendlongitudinally of the bed fore and aft of the machine at the right andleft hand sides or edges of the bed. The usual gelatin duplicating band54, connected at its ends as usual to winding spindles i5 journalled inthe frame, is stretched over and rests upon the bed H with the usualresilient gelatin coating of the band uppermost where the band lies uponthe bed.

Reciprocable over the bed longitudinally of the bed or fore and aft ofthe machine is an impression roller carriage IS in which is journalledat H the usual pivoted yoke it provided with the usual operating handleis and having journalled in its rearwardly extending arms at 26 theusual impression roller or platen roller M by which the sheets are laidand impressed upon the gelatin surface of the duplicating band it. Fixedto the carriage is the usual paper feed table 22, and there is alsopreferably mounted in the carriage the usual paper feed roller 23between which and the platen roller a sheet is fed in the usual mannerfrom the paper table. Any suitable known mounting for the usual feedroller 23 may be provided, such as that shown in my Patent No.1,983,517, granted December 11, 1934. Rearward thrust on handle 59lowers platen roller 2! relatively to the carriage to its workingposition in the carriage, which position is that shown in Figs. 1 and 2and is determined by suitable stops 34 on the carriage which are engagedby the yoke to limit the extent of lowering movement of the roller 2!relatively to the carriage. Forward pull on the handle elevates theroller 2! in the carn'age to inactive position.

The features above described are known and the improvements will now bedescribed.

At its right hand end the carriage i6 is formed with a pair of parallelarms 24 spaced apart fore-and-aft of the machine and which, when 55 thecarriage lies over the bed, curve outwardly and downwardly around track52 to a point below and outside of said track. These arms are connectedby an upstanding flat web or plate 25, preferably formed integrally withthe arms as shown, said web being disposed substantially verticallyedgewise when the carriage overlies the bed in working position, asshown.

A horizontally disposed guiding and supporting cylindrical rod 26 forthe carriage is fixedly and stationarily held at each end of said rod tothe machine frame 10 in any suitable manner, such as that shown at 2'1,for example, with said stationary rod extending fore-and-aft of themachine parallel to and below track l2 and parallel to the adjacentright hand longitudinal side edge of the bed ll.

Mounted on rod 26 to slide thereon and to rotate thereabout about theaxis of the rod is a yoke comprising a pair of parallel side arms 28formed integrally with a cross member or connecting member 29, whichlatter member is curved or bowed to partly encircle the rod and isprovided at one longitudinal edge thereof with an abutment face 36, andis provided at the other longitudinal edge thereof with a central arm orextension 3i having an abutment face 32 parallel or approximately so toabutment face 30, the two abutment faces being at opposite sides of rod26 and facing in the same direction. Arms 28 are rotatively and slidablyjournalled on rod 26 adjacent to connecting member 29 and have theirouter ends connected by suitable horizontal pivots or journals 33 to theouter lower ends of the arms 24 of the carriage, so that the carriagemay pivot relatively to the yoke about a horizontal axis whose levelvaries with the rocked position of the yoke 2829 about rod 26.

Plate or web 25 integral or rigid with the carriage is provided adjacentits lower edge with an abutment face 35 opposed to abutment face 30 ofthe yoke 2829. Fixedly held to web 25, and extending therethrough at aright angle thereto and adjacent the upper edge thereof, is a housing 36the inner end face 36 of which constitutes an abutment face opposed toabutment face 32 on the yoke 28--29. The relation of the abutment faces30 and 32 on the yoke ZS-29 to the abutment faces 35 and 36 on thecarriage are such as to permit a limited rocking or pivotal motionbetween the carriage and said yoke, as shown, that is faces 30 and 35cannot contact at the same time as faces 32 and 36 Normally in theworking position of the carriage both the pair of opposed faces 32 and36 and the pair of opposed faces 30 and 35 are yieldingly held out ofcontact by resilient means the force of which is adjustable. Thisresilient means comprises a spring-pressed plunger the head 37 of whichslides in the reduced inner end portion 38 of an axial bore in thehousing 36. The plunger has a stem 39 telescopically slidable in a bore40 in the head and encircled by a coiled spring 4|, which spring abutswith its ends the adjacent or opposed ends of the head of the plungerand an externally threaded head 42 formed on the stem 39 and screwedinto the internally threaded enlarged outer end portion 53 of the boreof housing 36. It will be obvious that, by screwing head 42 more or lessinto the threaded portion 43 of housing 36, the effect of spring 4! onthe plunger head may be varied. Spring H normally holds the plunger headpartly protruded from housing 35 with the rounded end of the headpressed against abutment face 32.

At its right and left hand sides or ends the carriage has journalledthereon for rotation about coincident axes the two supporting wheels orrollers 44 whose journals are so located that said wheels overlie tracksl2 and I3 in the working or bed overlying position of the carriage. Thelevel of the journals on the carriage is such, however, that said wheelsrest on or contact the tracks Only when the platen roller 2! is liftedout of working position or contact with the gelatin or a sheet lying onthe gelatin, and is such that lowering of the roller 2i into workingposition with yoke l 8 against stops 34 lifts the rollers t l off thetracks as shown in Figs. 1, 3 and 5. Rollers M and tracks l2 and it arethus effective to support the carriage out of contact with the gelatinband while roller 2| is lifted in the carriage but have no such effectwhen the roller fl is lowered in the carriage to working position.

When roller 2i is in working position the carriage is supported in partby the contact between roller 2! and the gelatin band or a sheet (mastersheet or copy sheet) interposed between the gelatin band and rollerduring sheet laying and impressing travel of the carriage and roller 2|rearward over the bed from the starting position for such laying andimpressing shown in Figs. 1 and 2, and said carriage is also supportedin part through the connections described above between the carriage androd 26, the latter connections serving also to guide the carriage. Itwill be obvious that spring ll sustains part of the weight of thecarriage and of the parts mounted thereon, including the platen roller,and also that the percentage of the total weight taken off the gelatinband may be varied by screwing the plunger stem 39-42 more or less intohousing 36. It will thus be observed that the carriage is more or lessresiliently supported through its connection with the machine frameduring sheet laying and impressing operations thereof and that thespring support may be varied, thereby permitting variation of the loadon the gelatin to enable attaining like intensity of ink transfer withsheets of different thickness and, if desired, heavy or lightimpressions on sheets of equal thickness.

It will also be observed that the carriage mounting is such that thecarriage may float up and down substantially in parallelism with the bedand may also teeter transversely of the bed, so that the impressionroller may follow Variations in surface height whether the variationsare longitudinal or transversely of the bed, thus greatly contributingto uniformity of pressure of the roller on all parts of a surface overwhich it is traversed.

The carriage mounting is also such that the carriage may be up-ended atone side of the bed as shown in Fig. '7, to afford free access to thebed when desired, as, for example, when it is desired to change theduplicating band. It will be obvious that, if the carriage is liftedupward and rightward, face 35 will quickly contact face Eli and that thecarriage and yoke will, thereafter, swing as a unit about rod 26. Inorder that the carriage may stand up-ended without having to be held upby the operator, the ma chine frame is provided with a ledge or flange35 lying below and to the left of rod 26 in ahorizontal plane andextending at least substantially the full length of said rod, the outeredge of which flange forms an abutment face which is contacted by anabutment face 46 on the web or plate part 25 of the carriage after thecarriage has been swung upward and rightward slightly beyond aperpendicular position, as shown in Fig. '7. The carriage may thus beupended at any point of its travel and into a position in which it willremain until it is purposely rocked back toward working position.

What I claim is:

1. In a duplicating machine of the hectograph type, the combination of abed for supporting the duplicating medium, a single guide rodfixedlyrelated to said bed, a support held to said guide rod to slidelongitudinally of the rod and to rotate about the rod, a platen rollersupporting carriage hinged to said support to swing relatively theretoabout an axis parallel to the rod, and means interposed between saidcarriage and support to yieldably resist swinging movement between thecarriage and support in the direction permitting approach of thecarriage to the bed.

2. In a duplicating machine, the combination of a frame, a bed thereon,a hectograph duplicating medium overlying and backed by the bed, aplaten roller carriage, a guide rod for the carriage supported in fixedrelation to the bed and extending longitudinally of the bed, meansconnecting one end of the carriage to said guide rod to constrain thecarriage to travel longitudinally of the bed and permit the carriage torise and fall substantially perpendicularly to the bed and also teetertransversely of the bed with the carriage extending transversely of andoverlying the bed and duplicating medium, a platen roller extendingbetween the ends of the carriage and mounted in the carriage forlowering of said roller to and lifting thereof from a predeterminedworking position in the carriage in which the carriage is supportedabove the bed and duplicating medium through said roller and saidconnecting means, said connecting means including spring means by whichsaid connecting means yieldingly sustains part of the weight of thecarriage while the carriage is supported through both said roller andconnecting means.

3. In a duplicating machine, the combination of a frame, a bed thereon,a hectograph duplicating medium overlying and backed by the bed,

a platen roller carriage, a guide rod for the carriage supported infixed relation to the bed and extending longitudinally of the bed, meansconnecting one end of the carriage to said guide rod to constrain thecarriage to travel longitudinally of the bed and permit the carriage torise and fall substantially perpendicularly to the bed and also teetertransversely of the bed with the carriage extending transversely of andoverlying the bed and duplicating medium, a platen roller extendingbetween the ends of the carriage and mounted in the carriage forlowering of said roller to and lifting thereof from-a predeterminedworking position in the carriage in which the carriage is supportedabove the bed and duplicating medium through the medium of said rollerand said connecting means, said connecting means including spring meansby which said connecting means yieldingly sustains part of the weight ofthe carriage while the carriage is supported through both said rollerand connecting means, and means on the carriage and frame engageable inall positions of travel of the carriage to support the carriage androller out of contact with the duplicating medium only while the rolleris lifted out of its working position, said engageable means beingseparated by lowering of the roller to Working position in the carriage.

4. A duplicating machine having, in combination, an upwardly facing bed,a duplicating medium stretched over the bed, a platen roller supportingcarriage, a platen roller in the carriage, a guide rod for the carriageextending longitudinally of the bed adjacent and parallel to onelongitudinal edge of the bed and supported in fixed relation to saidbed, and means connecting one end of said carriage with said guide rodto permit reciprocation of the carriage and roller longitudinally of thebed over the bed and medium with the carriage and roller extendingtransversely of the bed and to permit said carriage and roller to movesubstantially perpendicularly to said bed and also to teetertransversely of the bed during such reciprocation with part of theweight of the carriage yieldingly transmitted through said connectingmeans to said fixedly supported guide rod and the remainder of theweight of the carriage transmitted to the duplicating medium and bedthrough said platen roller.

5. A duplicating machine having, in combination, an upwardly facing bed,a duplicating medium stretched over the bed, a platen roller sup portingcarriage, a platen roller in the carriage, a cylindrical guide rod forthe carriage extending longitudinally of the bed adjacent and parallelto one longitudinal edge of the bed and supported in fixed relation tosaid bed, rigid means slidably and pivotally held to said rod and hingedtoone end of the carriage for hinge movement therebetween and thecarriage about an axis parallel to the rod, resilient means interposedbetween said rigid means and the carriage and coactive therewith topermit reciprocation of the carriage and roller over the bedlongitudinally of the bed with the carriage and roller extendingtransversely of the bed and with said carriage yieldingly urged upwardlyby said resilient means and said rigid means.

6. A duplicating machine having, in combination, an upwardly facing bed,a duplicating medium stretched over the bed, a platen roller supportingcarriage, a platen roller in the carriage, a guide rod for the carriageextending longitudinally of and parallel to the bed and supported infixed relation to said bed, rigid means slidably holding the carriage atone end to said rod for movement of the carriage about two parallel axesone of which is coincident with the rod axis, said means permittingreciprocation of the carriage and roller over the bed with the carriageand roller extending transversely of the bed, and spring meansinterposed between the carriage and said rigid means to tend to liftsaid end of the carriage during reciprocation of the carriage and rollerover the bed with the carriage and roller overlying and extendingtransversely of the bed.

7. A duplicating machine, as claimed in claim 4, having means adjustableat will to vary the proportion of the weight of the carriage sustainedby said connecting means between the carriage and guide rod.

8. A duplicating machine, as claimed in claim 6, having means adjustableto vary the lifting force exertable by the spring means on the carriage.

9. A duplicating machine, as claimed in claim 4, wherein said connectingmeans permits upending of the carriage at said longitudinal edge of thebed.

10. A duplicating machine, as claimed in claim 5, having abutment meanson the carriage and said rigid means for limiting the hinge movementtherebetween, and having fixed means coactive with said carriage andsaid rigid means in all positions of travel of the carriage along thebed to permit swinging of the carriage and said rigid means about theguide rod and arrest such swinging when the carriage reaches an up-endedposition in which it will remain until positively reversely swungtherefrom.

11. A duplicating machine having, in combination, a frame, an upwardlyfacing bed fixedly supported thereon, a duplicating medium extendingover and resting on the bed, a platen roller carriage, a cylindricalguide rod for the carriage supported in fixed relation to the bed withsaid rod extending longitudinally of and parallel to the bed, rigidmeans slidably and pivotally held to said rod for travel along the rodand turning about the axis of the rod, means pivotally connecting saidrigid means with one end of the carriage for a slight positively limitedhinge movement between said rigid means and carriage about an axisparallel to the axis of the rod with the carriage and rigid means foldedupon each other and with the carriage extending across the rod to saidhinge connection, means on the carriage and frame engageable at oppositelongitudinal sides of the bed to support the carriage for travel overthe bed longitudinally of the bed out of contact with the duplicatingmedium, a platen roller mounted in the carriage to extend transverselyof the bed when the carriage is supported any position of its travelalong the bed, through its connection with the guide rod, and the framecarries stationary means engageable by the carriage when the latter isup-ended at any point in its travel to support the carriage in up-endedposition through its connection with the guide rod.

13. A duplicating machine having, in combination, an upwardly facingbed, a duplicating medium extending over and resting on the bed, acylindrical guide rod supported in fixed parallel relation to one edgeof the bed, a platen roller for impressing sheets on said medium, acarriage for said roller, a support slidably and. pivotally held to saidrod, and a spring-hinge connection between said support and one end ofthe carriage holding said carriage to the support with the carriageextending across the rod to said hinge connection, the axis of whichconnection is parallel to the rod axis, said support and spring-hingeconnection resilientlyv transmitting part of the weight of the carriageto the guide rod. I

CHARLES H. BRADT.

